Reentrant superconductivity in proximity to a topological insulator

TL;DR

This paper studies how a helical magnetization in a topological insulator affects the critical temperature in a superconductor/topological insulator junction, revealing nonmonotonic behavior due to proximity effects.

Contribution

It introduces a self-consistent approach using Usadel equations to analyze the impact of in-plane helical magnetization on $T_c$ in S/TI junctions, highlighting a novel nonmonotonic dependence.

Findings

Critical temperature exhibits nonmonotonic behavior with TI layer thickness.

Helical magnetization influences superconducting proximity effects.

Method based on Matsubara Green's functions provides new insights.

Abstract

In the following paper we investigate the critical temperature $T_c$ behavior in the two-dimensional S/TI (S denotes superconductor and TI - topological insulator) junction with a proximity induced in-plane helical magnetization in the TI surface. The calculations of $T_c$ are performed using the general self-consistent approach based on the Usadel equations in Matsubara Green's functions technique. We show that the presence of the helical magnetization leads to the nonmonotonic behavior of the critical temperature as a function of the topological insulator layer thickness.